A pedestrian makes his way long Turner Road in Scituate, Mass on March 13, 2018.

CJ Gunther, EPA-EFE

What happens in the Arctic doesn't stay in the Arctic.

Extreme winter weather across the U.S. is linked to unusual warmth in the Arctic, according to a study published Tuesday.

That is especially true in the heavily populated eastern U.S., the study said, where extreme winter weather is two to four times more likely when temperatures in the Arctic are unusually warm.

The research comes out as the wild winter of 2017-18 comes to its (hopefully) merciful close with yet another nor'easter blasting the Northeast.

In addition to the onslaught of powerful storms, the winter also included a freakish, record-breaking cold snap over the eastern U.S. in late December and early January. At the same time, the Arctic was record warm, said Judah Cohen, director of seasonal forecasting at Atmospheric and Environmental Research and lead author of the study.

The theory is that when weird warmth invades the Arctic, some of the cold that's supposed to stay up there — including the infamous polar vortex — instead sloshes down south into North America and Europe.

"Warm temperatures in the Arctic cause the jet stream to take these wild swings, and when it swings farther south, that causes cold air to reach farther south," said study co-author Jennifer Francis, a climate scientist at Rutgers University.

Francis has been at the forefront of recent scientific research into how the weather and climate of the Arctic affects our weather here in the U.S.

"Five of the past six winters have brought persistent cold to the eastern U.S. and warm, dry conditions to the West, while the Arctic has been off-the-charts warm," she added. "Our study suggests that this is no coincidence. Exactly how much the Arctic contributed to the severity or persistence of the pattern is still hard to pin down, but it's becoming very difficult to believe they are unrelated."

This is the first study that also says heavy snow — in addition to extreme cold — could be tied to Arctic warming. In the study, scientists compared weather reports from the Arctic and 12 U.S. cities from 1950 to 2016.

The study also found that since 1990, while the frequency of cold episodes in the eastern U.S. has increased, it's actually decreased in the western U.S. as Arctic warming has become more pronounced.

Richard Alley, a leading glacier and climate expert at Penn State who was not involved in the research, told the Guardian that the study is “fascinating” and “important,” but added the discrepancy between Arctic temperatures and winter weather elsewhere could have other drivers, such as a warm Gulf of Mexico feeding extra energy into storms along the East Coast.

Another meteorologist not involved in the study, Ryan Maue of weather.us, said "it's not exactly a ground-breaking or high-impact paper" but noted it's a timely contribution to the rather uncertain weather connections between the Arctic and the U.S.

"While no firm scientific consensus exists in the climate community on these Arctic 'extreme' interactions, this research communication will help direct future research and spur timely debate on a high-impact climate-change problem," Maue said.